On 09/12/2013 12:26 AM, Srivatsa S. Bhat wrote: > On 09/12/2013 11:22 AM, Viresh Kumar wrote: ... >> Now coming back to the ideas I have... >> Same code will work if hotplug sequence is fixed a bit. Why aren't we doing >> exact opposite of suspend in resume? >> >> We are removing CPUs (leaving the boot cpu) in ascending order and then >> adding them back in same order.. Why? >> >> Why not remove CPUs in descending order and add in ascending order? Or >> remove in ascending order and add in descending order? > > I had the same thought when solving this bug.. We have had similar issues with > CPU hotplug notifiers too: why are they invoked in the same order during both > CPU down and up, instead of reversing the order? I even had a patchset to perform > reverse-invocation of notifiers.. http://lwn.net/Articles/508072/ > ... but people didn't find that very compelling to have. I'm not sure if you're talking about the order the CPUs get plugged back in after resume, or the order of the (pair of?) notifiers that gets called for each individual CPU. Sorry if this is blindingly obvious, but with CPU hotplug, I can manually unplug/re-plug CPUs in any order I feel like, and cpufreq had better work if I do that. Given that, I don't think there's any particular need for suspend/resume to unplug/re-plug CPUs in any particular order for correctness at least, although perhaps it'd be nice cosmetically for some reason? -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
